Client API Considerations
There are a number of optimizations to take into consideration when reading or writing data from a client using the Apache HBase API. For example, when performing a large number of PUT operations, you can disable the auto-flush feature. Otherwise, the PUT operations will be sent one at a time to the region server.
Whenever you use a scan operation to process large numbers of rows, use filters to limit the scan scope. Using filters can potentially improve performance. This is because column over-selection can incur a nontrivial performance penalty, especially over large data sets.
Tip
As a recommended best practice, set the scanner-caching to a value greater than the default of 1, especially if Apache HBase serves as an input source for a MapReduce job.
Setting the scanner-caching value to 500, for example, will transfer 500 rows at a time to the client to be processed, but this might potentially cost more in memory consumption.
